the association between two variables, x and y, with the influence of one or more other variables (z1, z2) statistically removed, controlled, or held constant; the effect of the z variable is removed from both x and y. For example, the partial correlation between salary and education level can be examined after the effects of age on each are removed. It is often of interest to learn whether a correlation is significantly reduced in magnitude once a third variable is removed. Also called higher order correlation; higher order partial correlation. Compare part correlation; zero-order correlation.